diff --git a/koha-tmpl/intranet-tmpl/prog/js/messaging-preference-form.js b/koha-tmpl/intranet-tmpl/prog/js/messaging-preference-form.js
index c6d97e7e19..01951afd8d 100644
--- a/koha-tmpl/intranet-tmpl/prog/js/messaging-preference-form.js
+++ b/koha-tmpl/intranet-tmpl/prog/js/messaging-preference-form.js
@@ -11,7 +11,8 @@ $(document).ready(function () {
     if ($("#messaging_prefs_loading").length) {
         $("#categorycode_entry").change(function () {
             var categorycode = $(this).val();
-
+            // if we change category, consider the messaging prefs dirty
+            message_prefs_dirty = true;
             // Show the combined modal and reset checkboxes to checked
             $("#categoryChangeUpdateMessaging").prop("checked", true);
             $("#categoryChangeUpdateExpiry").prop("checked", true);